Singer Neil Diamond has announced he will retire from touring, after a recent diagnosis of Parkinson's disease.

Diamond, who turns 77 on Wednesday, cancelled his March tour dates for Australia and New Zealand on medical advice.

The Solitary Man singer was midway through his 50th anniversary tour.

In a statement he said he took the decision "with great reluctance and disappointment".

"I have been so honoured to bring my shows to the public for the past 50 years," he said.

"My sincerest apologies to everyone who purchased tickets and were planning to come to the upcoming shows."

Parkinson's is a progressive condition in which the brain becomes damaged. It can lead to tremors, difficulty moving, speech changes and eventually memory problems.

Diamond hopes to continue writing and recording for some time to come, a post on his website reads.

"My thanks goes out to my loyal and devoted audiences around the world," he said. "You will always have my appreciation for your support and encouragement."

With a nod to his hit Sweet Caroline, he added: "This ride has been 'so good, so good, so good' thanks to you."

Diamond, who has sold over 130 million albums worldwide, is set to receive a lifetime achievement award at Sunday's Grammy Awards.

Friends and fans sent their best wishes to the singer on social media as news of his retirement spread.

"Keep fighting, old buddy. You've got a long way to go yet," tweeted singer Nancy Sinatra.

"Endless admiration and love to you," wrote musician Josh Groban.

Rolling Stone contributing editor David Wild said Diamond was behind "the kindest thing any star ever did for me".